When a developer is developing a web application, often there is a need to reuse existing resources. A widget is an example of such an existing resource. To enable existing resources to be reused by other web pages, it is necessary for a resource provider to provide a common application program interface (API) for resources so as to be used by the developer. However, for the resource provider, providing a common API takes additional cost, therefore, in some cases, the resource provider often does not provide a common API. In case the resource provider does not provide a common API, it is difficult to reuse these resources.